There are various types of locking devices that are used to support equipment in the production string of oil and/or gas wells. Generally, these locks can be unlocked with a pressure differential existing across them. However, releasing a well lock under pressure with a wire line tool may cause the released lock and line to be blown up the hole creating a tangled mess of wireline which may cause a costly wireline fishing job and even pulling of the tubing string to remove the obstruction.
The present invention is directed to an improved method and apparatus for setting and releasing a well lock from a landing or locking nipple in oil and/or gas wells which may be subject to high pressures.